Die-stock.



H. w.-osTER E w. J. MAGAK.

Patented Nov. 10, 1914 UNITED STATES PATENT OEEICE.

HERMAN W..0STER AND'WILLIAM J. MACAK, OF CLEVELAND, OHIO, ASSIGNORS T0 THE OSTEB MANUFACTURING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

il ,1l 16,838.

Specification of Letters Patent.

anni-sweex'.

. Patented Nov. 10, 1914.

To all whom it may concern:

Be it known that gwe, HERMAN W. Os'rER and WILLIAM il. MACAK, citizens of the United States, and residents of Cleveland, in the county ot Cuyahoga and State of hio, have invented a certain new and useful lmprovement in Die-Stocks, of which the following is a full, clear, and exact description.

rlhe object of thisin'vention is to provide a cheap and eilicient die stock wherein the dies will gradually recede as the thread is being cut, whereby they will cut what is known as tapered threads.

The invention consists in the construction and combination of parts hereinafter described and pointed out definitely in the claims and shown in the accompanying drawings whereinlrigure l is a centrallongitudinal sectional view, and Fig. 2 is a front end view with certain parts broken away.

lhe work holder l is of familiar construction, being a built up member of tubular form, so that the pipe or cylindrical piece ot' work to he threaded may be' passed through it, and beine provided with suit-4 able means whereby it may he clamped to the work. rl`he die carrier 2. is likewise tuba'- lar, and is capable of being moved rotatably and longitudinally relative to the work holder. ln the construction shown the die carrier has its rear end externally threaded so that it may loe screwed into the' internally threaded work' holder; wherefore as the die carrier is turned relatively to the work holder it will move longitudinally relati ve thereto at such a rate as is determined hy the pitch ot the engaging screw threads..

.lit the front end of the die carrier is an outwardly' extended tlange 2 which is provided with a plurality of pairs ot forwardly projecting lugs 2b, 2c, which serve as guideways to determine the path ot movement of the die cases l which lie between them. These die cases have rihs la on their sides which gointo the grooves in the inner faces orEE these lugs. The dies il are tted into these die cases. Ilhe rear end ot each ahuts a shoulder l" on the associated die case, and it is held down by gihs te which are fixed to the top edges ot the die case, so as to overhang and engage with the die therein.

5 represents a ring which is rotatively monnted on the worlr holder, hut is held against longitudinal movement,-the particular means shown for accomplishing this result being an annular groove l in the work holder, and one or more pins 5 which screw through the ring and project into this groove. rlhis ring has outwardly projecting lugs 5, which lugs may be parts of a continuous flange, if desired. Through each of these lugs a hole 5 is formed; and through each of these holes passes a 'lever 6. The rear end of this lever is pivoted to inwardly projecting ears 2d formed on the rear end of.l an arm 2 which is fixed to the flange 2a of the die carrier, and is enten rearward therefrom outside of and past said ring. These so-called arms are parts of a cylindrical lllange,-but the parts of the nange betweenthe so-called arms have no other function than to furnish a housing over the ring and levers. Each lever 6 from its pivot to its front end extends through the hole 5 and at a slight angle toward the axis ot' the tool. lts upper end passes through a slot 2g in the flange 2 and enters a recess et in the rear face of the associate die case. rlhis recess and end of the lever are curved so that they will fairly well t each other under all conditions. Moreover, the inner and outer margins of the holes 5C are so shaped that the lever will have an operative engagement with them under all coi,.- ditions. llf'hen, now, the die carrier is screwed into the worlr holder, the lever 6 will, of necessity, since it passes through the hole 5C, he caused to assume e position more and more nearly parallel with the asis of the tool. This will compel an outward move ment ot the die case and die carried thereby,

or it will control such outward movement when produced hy the out-thrust ot the work upon the dies. ln other words, the die cases and dies will gradually recede asv a thread is being cut upon a pipe properly held in the work holder so that the thread so cut will be what is known as a tapered thread.`

Having described our invention, what we claim iszl. lai a die stock, the combination of a work holder, a die carrier which is rotatable and movable longitudinally relative to the work holder, radially movable dies carried hy the die carrier, a ring which is rotatably mounted on the worltholder but is held. against longitudinal movement thereon, which ring has longitudinal holes extended through it, arms fixed to the die car rier and extending rearward outside of and past the ring, and levers pivoted to said arms and extended through the holes in the ring, and means transmitting motion of the front ends of said levers to said dies.

2. ln la die stock, the combination of a work holder, a die carrier which is rotatable and movable longitudinally relative to the work holder, radially movable dies carried by the die carrier, a ring which is rotatably mounted on the work holder but is held against longitudinal movement thereon,

which ring has longitudinal holes extended through it, arms fixed to the die carrier and extending rearward outside of and past the ring,.die eases which are radially movable on the die carrier and in which the dies are xedly held, said cases having in their rear aoes curved recesses which receive respectively the front ends of said levers.

1n athread cuttin device, a stock body adapted to carry a 'e, a leader bushing screwing upon said body and adapted to be fastened to the work, a rotatable laterally xed ring, and a lever operatively engaging said die and being Controlled jointly by said ring and stock body, said lever being ob lique to the axis of the stock body and being pivoted to one of the two last mentioned parts and always engaging the other of said parts at a point having 'a iixed distance from the axis o rotation and a xed position lengthwise of the axis of rotation.

in testimony whereof, we hereunto aix our signatures in the presence of two witnesses.

HERMAN W. @STER ilLLlAlld J. MACAK.

Witnesses:

H. R. SULLIVAN, E. L. TnUnsaoN. 

